• Korean Journal of Pharmacognosy
• /
• v.45 no.4
• /
• pp.282-287
• /
• 2014

The ORI2 (3-[3,4-dihydroxyphenyl]acrylic acid 1-[3,4-dihydroxyphenyl]-2-methoxycarbonylethyl ester) was purified from the extract of Isodon excisus. We confirmed the antiviral effect of ORI2 in a coxsackievirus-induced pancreatitis model. Coxsackievirus B4 (CVB4) is a common cause of pancreatitis and may be reason of the type-1 diabetes. Anti-enteroviral compounds were screened by HeLa cell survival assay. Purified natural compounds were added to HeLa cells cultured 96-well plates after $10^4PFU/ml$ CVB4 pre-incubation for 30 min. ORI2 significantly improved HeLa cell survival in a dose-dependent manner. In addition, ORI2 (1 mM) treatment was dramatically decreased virus protease 2A induced eIF4G-I cleavage and viral VP1 capsid protein production. HeLa cell virus titers and viral RNA replication were significantly decreased in ORI2-treatment in a dose dependent manner (1 mM~0.001 mM). These results demonstrate that ORI2 has a strong antiviral effect. It was significantly decreased virus replication. ORI2 may be developed as a potential therapeutic agent for CVB4.

• Korean Journal of Pharmacognosy
• /
• v.47 no.2
• /
• pp.137-142
• /
• 2016

Enterovirus is a common cause of several severe diseases such as myocarditis, hand-foot-mouth disease, and meningitis in children and adult. There are many try to develop new antiviral drug for direct treatment in virus infection. However, synthetic chemical antiviral drug is not working. To overcome this limitation, we examined plant extracts. The antiviral effect of plant extracts was screened by HeLa cell survival assay in coxsackievirus B3 (CVB3) infection. We observed a strong antiviral effect of Poria cocos extract in a dose-dependent manner (1 mg/ml~0.01 mg/ml). P. cocos extract (1 mg/ml) treatment was dramatically decreased virus protease 2A induced eIF4G-I cleavage and virus capsid protein VP1 production. CVB3 positive and negative strand RNA amplification were significantly reduced in P. cocos extract treatment. P. cocos extract completely blocked early time activation of ERK and AKT activity in CVB3 infection. Taken together these data indicate that the treatment of P. cocos extract strongly inhibit CVB3 replication. Poria cocos extract may possible to developed as a therapeutic agent for enterovirus.

• BMB Reports
• /
• v.33 no.1
• /
• pp.59-62
• /
• 2000

Hepatitis C virus (HCV) nonstructural 5B (NS5B) protein is an RNA-dependent RNA polymerase (RdRp). To determine whether it can contribute to viral replication by interaction with cellular proteins, the yeast two-hybrid screening system was employed to screen a human liver cDNA library. Using the HCV NS5B as a bait, we have isolated positive clones encoding a cellular protein. The NS5B interacting protein, 5BIP, is a novel cellular protein of 170 amino acids. Interaction of the HCV NS5B protein with 5BIP was confirmed by a protein-protein blotting assay. Recently, we have demonstrated that NS5B possesses an RdRp activity and thus it is possible that 5BIP, in association with NS5B, plays a role in HCV replication.

• Korean Journal of Pharmacognosy
• /
• v.30 no.3
• /
• pp.238-243
• /
• 1999

This study was undertaken to test for anti-hepatitis B virus (HBV) activity of the aqueous extracts prepared from 9 medicinal plants of Korea (Cornus officinalis, Caesalpinia sappan, Rubus coreanus, Lycium chinense, Artemisia capillaris, Isatis tinctoria, Phyllanthus urinaria, Lysimachia christinae, Lonicera japonica). Aqueous extracts were tested for cytotoxicity and assayed for inhibition of HBV replication by measurement of HBV DNA and surface antigen (HBsAg) levels in the extracellular medium f HepG2 2.2.15 cells. The extract from Rubus coreanus, Artemisia capillaris, Phyllanthus urinaria decreased the levels of extracellular HBV virion DNA at concentrations ranging from 128 to $256\;{\mu}g/ml$ and inhibited the production fo HBsAg dose-dependently without showing cytotoxicity. Our findings suggest that these three hebal medicinal plants may have potential to develop as specific anti-HBV drugs in the future.

• YAKHAK HOEJI
• /
• v.43 no.4
• /
• pp.458-463
• /
• 1999

This study was undertaken to test for antiviral activity of the aqueous extracts prepared from 4 medicinal plants of Korea (Terminalia chebula, Sanguisorba officinalia, Rubus coreanus, Rheum palmatum). Aqueous extracts were assayed for the inhibition of hepatitis B virus (HBV) replication by measurement of HBV DNA and surface antigen (HBsAg) levels in the extracellular medium of HepG2 2.2.15 cells. All extracts decreased the levels of extracellular HBV virion DNA at concentrations ranging from 64 to $128{\;}\mu\textrm{g}/ml$ and inhibited the production of HBsAg dose-dependently. Among the 4 tested plants, Terminalia chebula exhibits the most prominent anti-HBV activities. Our findings suggest that these 4 medicinal plants may have potential to develop as specific anti-HBV drugs in the future.

• Journal of Microbiology and Biotechnology
• /
• v.27 no.2
• /
• pp.380-387
• /
• 2017

The foamy viruses are currently considered essential for development as vectors for gene delivery. Previous studies demonstrated that prototype foamy virus (PFV) can infect and replicate prevalently in a variety of cell types for its exclusive replication strategy. However, the virus-host interaction, especially PFV-transportin3 (TNPO3), is still poorly understood. In our investigation of the role of TNPO3 in PFV infection, we found lower virus production in TNPO3 knockdown (KD) cells compared with wild-type 293T cells. PCR analysis revealed that viral DNAs were mostly altered to circular forms: both 1-long terminal repeat (1-LTR) and 2-LTR in TNPO3 KD cells. We therefore suggest that TNPO3 is required for successful PFV replication, at least at/after the nuclear entry step of viral DNA. These findings highlight the obscure mysteries of PFV-host interaction and the requirement of TNPO3 for productive infection of PFV in 293T cells.

• YAKHAK HOEJI
• /
• v.43 no.5
• /
• pp.623-628
• /
• 1999

DA-125, a new antitumor agent, was compared with adriamycin, a known DNA intercalator, in terms of inhibitory mechanism of DNA replication by using replicating simian virus 40 (SV40) genome in vivo. In analyzing the SV40 DNA replication intermediates present in cells treated with DA-125, it was not observed to accumulate B-dimers of SV40 DNA which are prominent in adriamycin-treated cells. However, treatment with DA-125 induced dose-dependent formation of DNA-topoisomerase complex which is characteristic of topoisomerase poisons. In addition, DA-125 showed more efficient in inhibiting SV40 DNA replication than adriamycin. Therefore, on the basis of this observation, we suggest that DA-125, a derivative of adriamycin, inhibits DNA replication by blocking topoisomerase activity as a toposomerase poison although adriamycin blocks topoisomerase activity as a DNA intercalator.

• Korean Journal of Microbiology
• /
• v.38 no.3
• /
• pp.221-229
• /
• 2002

Japanese encephalitis virus (JEV) persistence was established and maintained in Vero cell culture for over 1 year. Eleven clones of plaque morphology mutant JEV, with large and small plaque sizes, were obtained from the cell culture supernatant. Genomic RNA replication efficiency of the mutants in naive Vero cell appeared to correspond to their different plaque sizes. No significant changes in envelop protein ORF or in non-coding regions at both ends of the RNA genome suggested that there could be an unidentified factor(s) playing role in JEV attenuation. Unlike to the replication of wild-type JEV, the mutants did not induce severe degree of cytopathic effect in Vero cells upon infection. While obvious decrease of Bcl-2 and its mRNA expression and sharp increase of p53 in naive Vero cells infected with either wild-type JEV or the large plaque-forming mutant, those changes were not observed with the small plaque-forming one. Together with these observation, internucleosomal DNA fragmentation and chromosomal DNA profile in the Vero cells infected with the mutants suggest that an overall changes in cytopathic effect in the plaque morphology mutants-infected cells should be primarily due to the reduced genomic RNA replication and the compromised degree of p53-independent apoptosis by the virus infection at least in part.

• The Plant Pathology Journal
• /
• v.36 no.3
• /
• pp.280-288
• /
• 2020

RNA interference (RNAi) has attracted attention as a promising approach to control plant viruses in their insect vectors. In the present study, to suppress replication of the rice stripe virus (RSV) in its vector, Laodelphax striatellus, using RNAi, dsRNAs against L. striatellus genes that are strongly upregulated upon RSV infection were delivered through a rice leaf-mediated method. RNAi-based silencing of peroxiredoxin, cathepsin B, and cytochrome P450 resulted in significant down regulation of the NS3 gene of RSV, achieving a transcriptional reduction greater than 73.6% at a concentration of 100 ng/μl and, possibly compromising viral replication. L. striatellus genes might play crucial roles in the transmission of RSV; transcriptional silencing of these genes could suppress viral replication in L. striatellus. These results suggest effective RNAi-based approaches for controlling RSV and provide insight into RSV-L. striatellus interactions.

• The Plant Pathology Journal
• /
• v.17 no.6
• /
• pp.389.3-389
• /
• 2001